Prevention is an area of growing importance in the field psychiatry, although very few books have been written on the subject. Topics covered in this important issue include: Prevention of depression in older; Prevention of dementia; Use of genetics as a tool for prevention of mental illnesses; Successful cognitive and emotional aging; Internet Depression Prevention; Prevention of First Episode of Psychosis; Prevention of Adolescent Depression; Prevention of Post-Partum Depression; Prevention of PTSD; Prevention of metabolic syndrome in people on antipsychotics, and others.